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hello all, what weight enging oil should i use for myu 1949 235 engine? thanks alot

1949chev34,

For normal every day driving 30 weight would be fine. If the motor is worn out or a leaker, you could move up to a 40 weight. Non detergent is still available if you search for it but detergent is much more prevalent. My bet would be your engine has been running 30 weight detergent and this would be the best choice to stick back in it.

Multi-grades are cool, but for your '49, it makes little economic sense and the old engine might go on strike with the fancy stuff.

Stuart

thanks alot stuart

I agree, SAE 30 is all I run in my 39 which has a 48 235 currently. Manual calls for 20 weight, but in AZ I don't worry about the Winter too much. I haven't considered 40 weight myself since cranking a 6 volt to life is challenging enough with all that gooey 30 weight sloshing around cold.

40 weight is too heavy for a dipper 235, in my opinion. I would use 10W30.

The multigrade oils arent so multigrade anymore after about 6000 - 8000 miles (we tested that in a Lab). You can try this at home. Poure a cup of 6000 mile oil in to a smal funnel and stop the time it takes till it is empty.
Than try this with the same brand@same temperature with the new oil.
Do it with oil out of a refigator and with Oil heatet to 100 deg Celsius and you will see what I mean.

Same is with the addditives in the high price mineral and synthitic oils.
They break down pretty soon.

I found this on te Wearchek website:

I recomend Shell Rotella SAE 30 because it will not ruin your cam like the newer Oils for modern cars plus a cup of your favourite "snake oil" additive.
We use Mathy here in Germany for 50 Jears with succsess, but I don`t think they sell it in the US.

AV-Blend has a similar formula an is a US Product. http://www.avblend.com/

Frank

I would agree on using the Shell Rotella SAE 30. It's readily available at Wal-Mart, K-Mart, Murrys, Target, Farm Supply, etc.
Never was much for additives in my daily drivers. I’ve driven every car/truck I have owned since 1958, and that’s a bunch, well over 100,000 miles and many close to 200,000 and have never used additives in them, that is, other than what was already in the oil or fuel. I am an advocate of frequent oil changes and believe that goes a long way in preventing problems. Just keep it clean and topped off and that should cover about 98% of your worries.

These older inliners tain’t built like the newer engines so even when they are in excellent condition expect to use a quart of oil every 1-2k. I you look in the Salesman Truck Data Book under Engine it mentions “Certified Oil Economy” Tests by the AAA on Chevrolet trucks 1500mi to a quart when hauling a load was considered good oil economy for the dippers.

AV Blend = 4-pack $79.80 (plus Shipping & Handling) or $20+ per 12oz can, a case of that buys a lot of oil changes from where I stand guys.
But if you’re a believer in motor honey then: http://www.casite.com/locator.asp?categoryID=14 and http://www.stp.com/ probably do the same thing as their ads read the same, and are a lot cheaper, I guess because their not “FAA certified.”
Denny Graham
Sandwich, IL

I see stovebold is making his own zahn cup.

Stovebold,

Interesting thoughts. My only comment is that after 6000 miles, it's a crap-shoot as to the condition of the test sample. If this sample didn't pass the 'pregnancy test', it would be a firm testament to changing your oil at 3000 mile intervals.

You are right about the VI improvers 'shearing'...that's what they are suppose to do. The part that was left out is that they (the molecules) repair themselves..this happens over and over until the oil is 'worn out'. This is when the ability to 'multi-vis' is gone...probably by the time you tested your 6000 mile oil.

There are several reasons why you change your oil at the suggested interval. One reason is the oil is 'full'..it has trapped and held all the contaminants it can and it needs to be changed. The other reason is that it is worn out...it is 'sheared to death' and offers little lubrication in those high stress areas like cam lobes and piston skirts.

This is how I understand this black magic.

Stuart

I use Quaker State 10W30 in my 49 (56-235) and in my 81 Malibu. I have 500,000 kilometres on the Malibu and have not opened the engine. I have changed the stem seals only. I change the oil in my 49 every 1000 miles (paranoia?) and every 2000 kilomtres in the Malibu.
Doesn't mean its correct, just what I've been doing.

thanks alot for all of your input. mike